Dynamic changes of DAZL and BOLL protein expression during development of the human fetal ovary.

<p>(<b>A</b>) at 65d gestation, DAZL is expressed in the nuclei and cytoplasm of germ cells in the human fetal ovary, but BOLL is not detected (<b>B</b>) At 14, 18 and 20 weeks gestation, DAZL is detected only in germ cell cytoplasm (arrows). BOLL-positive germ cells (arrowheads) are detectable from 14 weeks onwards, and increase in abundance with increasing gestation. Rare double-positive cells are marked by the asterisk. Primordial follicles at 20 weeks gestation (arrows, bottom left panel) express only DAZL. <b>C</b>) Tiled image of 18 weeks gestation fetal ovary section showing minimal co-localisation of DAZL and BOLL. DAZL is expressed in less mature germ cells in a more peripheral localisation, while BOLL predominantly expressed in more mature, centrally-located germ cells. Scale bar (A) and (B) 20 µm, (C) 50µm.